Solution:

This problem can be solved with similar triangles property.
The White triangle is similar to the Red one
Now Ratio of sides is 2:3 (as ratio of areas = ratio of based if the height is same)
Seeking that, White triangle = 9/4 * Yellow triangle = 9/2
Following all the above, the Green region = 5.5 units

Solution:

3

Solution:

8

Solution:

5:19

Starting with the watch on the left, add 42 minutes to the time shown to give the time on the next watch to the right

Solution:

18

Solution:

60

Solution:

40

Solution:

4

6*3 equals 18
7*9 equals 63
6*4 equals 24
7*6 equals 42, ? should be replaced by 4.

Solution:

17

It is the sum of the two digits(9 + 8) in opposite quadrant.

Solution:

13